Wireless healthcare systems are being increasingly used to help reduce healthcare cost, increase patient independence and provide better outcomes. A typical wireless healthcare system includes sensors, a host device or relay station, and a remote server. The sensors typically sense physiological signals from the body and wirelessly transmit them to a nearby host device or relay station. The host device receives the signals from the sensors and can then process and relay them to the remote server. The signal can be relayed using a cellular or other suitable type of network.
One critical aspect of remote monitoring of human physiological signals is to ensure that the privacy of the patient is maintained. Wireless transmission of these physiological signals needs to be protected against unauthorized detection of the signals. One method that can be used to ensure that patient information remains confidential includes encrypting data transmission with a 128-bit or better advanced encryption standard (AES) encryption scheme. Such a scheme involves sharing of private keys between the wireless patches and the host device prior to transmission. In order to accomplish this, sharing of private keys between the wireless patches and the host device prior to transmission can be done. This is feasible when the sensors and the host device could be purchased by patients at the same time, and also the host device could be reused with the same patch at different times. Another method is to ensure private key exchange by allowing the host device to program the keys into the sensors using near field communication so that nearby detectors cannot listen to the transmissions as the near field communication's range is only about 20 cm. Such a method can be used when it is practical to have an additional wireless method (magnetic field induction using 13.56 MHz bandwidth) that is different from the ones used by the wireless healthcare systems (radio frequency (RF) bands in the hundreds of MHz and in GHz) in the wireless patches and host device.
Therefore, a wireless healthcare system that is capable of eliminating detection of patient information by devices external to the system by operating at a low-power RF mode during the key-exchange period would be useful.